The 1966 Open Championship was the 95th Open Championship, held 6–9 July at Muirfield Golf Links in Gullane, East Lothian, Scotland. Jack Nicklaus won the first of his three Claret Jugs, one stroke ahead of runners-up Doug Sanders and Dave Thomas. It was the sixth of eighteen major titles for Nicklaus and marked the completion of the first of his three career grand slams.The 1966 Open was the first to be scheduled over four days, with one round each day, finishing on Saturday.